Improvement in fire-tubes for steam-boilers



UNITED STATES PATENT QFFICE.

HENRY BAILEY, OF NEW YORK, N. Y.

IMPROVEMENT IN FIRE-TUBES FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. l 66,! 80, dated August3, 1875; application filed July 1, 1875.

To all whom it may concern:

Be it known that I, HENRY BAILEY, of the city, county, and State of NewYork, have invent-ed a new and useful Improvement in the Fire-Tubes ofSteam-Boilers; and Ido hereby declare that the following is a full,clear, and exact description thereof, which will enable others skilledin the art to make and use the same, reference being had to theaccompanying drawings forming part of this specification.

The object of this invention is to render steam-boilers of the tubularclass more efiective in generating steam than they have heretofore been;and it consists of a series of metallic spiral sections connectedtogether, having spaces (one or more) between the sections which spacesserve as combustion-chambers. It also consists in the connecting link orrod, in combination with the spiral sections and combustion-chamber.

In the accompanying drawings, Figure 1 represents a longitudinal sectionof the improved boiler-tube. Fig. 2 is an outside View of the same,showing the tube broken away, and the spiral in dotted lines.

A is the tube. B isthe metallic spiral. G is the connection of thespiral sections. D is the space or combustion-chamber between the spiralsections. In the generation of steam in ordinary tubular boilers theheated gases and flame pass through the' tubes unobstructed, and carryofi a large percentage of the heat, which is wasted. In order to utilizethe whole of the heat, or nearly so, it is necessary to not Only retardthe current, but to throw it from the center to the surface of the tube,and to have one or more combustion chambers or spaces between spiralsections. The spiral sections are formed of strips of thin metal, whichare twisted or made spiral in any manner, so that when placed in thetube the heated gases and flame will pass readily and be thrown by thespiral from the center of the tube and to the surface, and be retainedin the tube a much longer space of time than they otherwise would.Between the spiral sections are the spaces D, which serve ascombustion-chambers for the more perfect consumption of the gases asthey pass through the tube. The spiral sections are connected togetherby the links or rods 0, so that the whole is flexible or chain-like.This flexibility is an important feature, as the spiral sections can beplaced in tubes Where the boilers are in use, and when the fire boxfront would form an obstruction if the spiral was not made in sectionsand thus connected together. The spiral sections are nearly the diameterof the interior of the tube, and the length of the combustion-ch amber Dmay be one foot, more or less. The spiral will, of course, vary in sizeaccording to the diameter of the tubes.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In combination with the spiral sections 13, the combustion-chamber D,for the purposes described.

2. The connecting link or rod G, in combination with the spiral sectionsB, for the-purposes described.

HENRY BAILEY.

Witnesses:

A. DE BEVOISE, JOHN 0. Hon.

